1. Technical Field
The present invention relates to an optical detection system, a program, etc.
2. Related Art
In electronic equipment such as a cellular phone, a personal computer, a car navigation system, a ticket vending machine, and a baking terminal, a display device with position detection function having a touch panel on the front surface of a display unit has been recently used. According to the display device, a user can point an icon of a displayed image or the like and input information while referring to images displayed on the display unit. As a position detection method using the touch panel, for example, a resistance-film method, a capacitance method, or the like is known.
On the other hand, in a projection display device (projector) and a display device for digital signage, their display areas are larger compared to those of the display devices of the cellular phone and the personal computer. Therefore, in these display devices, it is difficult to realize position detection using the above described touch panels according to the resistance-film method and the capacitance method.
As related art technologies of position detectors for projection display device, for example, the technologies disclosed in Patent Documents 1, 2 (JP-A-11-345085, JP-A-2001-142643) are known. However, in these position detector, it may be possible to detect the position of an object (user's finger, a pen-shaped device, or the like), but difficult to determine an input start (input designation command) and an input end (end designation command). Here, the input is executed in response to the position of the object. For example, in a character input system, the input start corresponds to the start of line drawing from the position of the object and the input end corresponds to the end of line drawing in the position of the object.
In the case where the determination of the input start and the input end is difficult, for example, in the case where character input is performed, it may be impossible to determine the point of starting character input (that is, it may be impossible to start writing characters), and it may be impossible to determine the end of character input (that is, all characters may be unicursal).